import cv2
import glob
import numpy as np

import fire


def calibration(des='01'):
    # termination criteria
    criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)

    # prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
    objp = np.zeros((6 * 7, 3), np.float32)
    objp[:, :2] = np.mgrid[0:7, 0:6].T.reshape(-1, 2)

    # Arrays to store object points and image points from all the images.
    objpoints = []  # 3d point in real world space
    imgpoints = []  # 2d points in image plane.

    images = glob.glob('../left/*.jpg')

    for fname in images:
        img = cv2.imread(fname)
        gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

        # Find the chess board corners
        ret, corners = cv2.findChessboardCorners(gray, (7, 6), None)

        # If found, add object points, image points (after refining them)
        if ret == True:
            objpoints.append(objp)

            corners2 = cv2.cornerSubPix(gray, corners, (11, 11), (-1, -1), criteria)
            imgpoints.append(corners2)

            # Draw and display the corners
            img = cv2.drawChessboardCorners(img, (7, 6), corners2, ret)
            cv2.imshow('img', img)
            cv2.waitKey(500)

    cv2.destroyAllWindows()

    ret, mtx, dist, rvecs, tvecs = cv2.calibrateCamera(objpoints, imgpoints, gray.shape[::-1], None, None)
    img = cv2.imread('../left/left' + str(des) + '.jpg')
    h, w = img.shape[:2]
    newcameramtx, roi = cv2.getOptimalNewCameraMatrix(mtx, dist, (w, h), 1, (w, h))
    # undistort
    dst = cv2.undistort(img, mtx, dist, None, newcameramtx)

    # crop the image
    x, y, w, h = roi
    dst = dst[y:y + h, x:x + w]
    cv2.imwrite('../calibresult/left' + str(des) + '.png', dst)


if __name__ == '__main__':
    fire.Fire(calibration)
